


Adrenaline Rush

by Suzuranao (IamLurking)



Category: Granblue Fantasy (Video Game)
Genre: Anal Sex, Blood and Injury, Drug Use, Feral Behavior, Forced Ingestion, M/M, Mating Cycles/In Heat
Language: English
Status: Completed
Published: 2020-06-01
Updated: 2020-06-01
Packaged: 2021-03-03 00:22:49
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,071
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24485812
Author URL: https://archiveofourown.org/users/IamLurking/pseuds/Suzuranao
Summary: Siegfried's awoken dragon blood seems to have laid dormant... Until it triggers a heat in him and induces a feral-like state again.It's up to Dr. Gran to subdue the unruly beast.Written for the kink meme
Relationships: Gran/Siegfried (Granblue Fantasy)
Comments: 6
Kudos: 43





	Adrenaline Rush

**Author's Note:**

> [Prompt: ](https://gbfkinkmeme.dreamwidth.org/523.html?thread=1035#cmt1035)"siegfried loses control of his faculties due to his dragon blood resurging, his meds are losing effectiveness. he essentially goes into heat and only calms down when he's fucked by doctor gran. bonus points if gran tries to force feed him sedatives to get him calmed down enough to be functioning"
> 
> I saw this and i just KNEW i had to write it. Feed me more feral siegfried/gran prompts and content please im starving.
> 
> The actual hornt turned out to be so short sobs, i hope u like lengthy buildup and a bit of sap at the end.

There was a distant crash in the infirmary. Metal bending, snapping and hitting walls, doors. Loud enough Gran looks up in alarm and drops what he was doing a floor above, drawing his weapon from its holster and breaking into a run, leaving the party mid-conversation.

He could explain it later to them, but the no-longer restrained patient shouldn’t wait if he didn’t want Noa to hang him by his big toe from the lookout.

He jumps the stairs three at a time to the lower level, almost barrelling into someone he doesn’t bother to identify, shouting at bystanders to please keep everyone out from this floor. Last time he had to break a wall and he’d rather not injure someone not involved and have to explain later.

The creak of metal is getting stronger and he barely has time to unlock the door and slam it close behind him before the chain snaps and he’s pressed up against the frame violently. Hot, damp breath teases his neck as one clawed hand digs in the wood beside his face, splinters raining noiselessly to the floor. The other presses against his shoulder painfully, tearing through his coat but stopped by his thick, protective scrubs before it can reach his skin.

A menacing, inhuman sound fills the room as long, damp brown strands of hair shield a face that looms over him.

Siegfried is awake.

* * *

His awoken dragon blood seemed to have slowed its spread almost to a halt, changes not even noticeable at first to Siegfried himself who monitored himself almost overzealously for weeks on end, months, until it had been tucked carefully on the back of his mind. Always there but no longer an overbearing concern that consumed every existing moment.

Until that morning, where he’d felt feverish, as if coming down with a seasonal illness as it was normal for this time of the year. Except the last time he had spring fever had been more than a decade ago, before he’d ventured in that cave and been dragged back to life by Fafnir’s blood.

And then in the span of a few hours it steadily grew worse until he was reduced to a loose beast in the middle of a long trip, no port nearby, not even any deserted island to make an emergency docking.

Destruction was not his sole aim as it had been then, but there was no reasoning with such a feral creature. There was only subduing until they could find help to treat him temporarily.

Or put him down for good.

But Gran was absolutely adamant against it, and he’d made use of all his knowledge after magic failed. He’d got Siegfried to fall asleep with a concoction earlier, knowing it would be a temporal measure, and yet he didn’t think it would take him only a few hours to shake off something that would induce a week-long coma in a normal person.

He swallows in reflex, adrenaline and fear making sweat break out in his skin. He has no delusions about how close he is to death in this moment. Siegfried could lean in and tear out his throat with his teeth and it would be so swift Gran would barely have any time to register it before he chokes on his own blood, held upright by the clawed hand in his shoulder as Siegfried drinks from him until he’s dry.

Gran does not breathe deeper than a shallow whisper, finger twitching minutely on the trigger of his weapon. But it’s loaded on the wrong cartridge, on healing potions as he’d been busy patching up other crew members when his ears caught the first sound of trouble. 

A bead of sweat rolls down his neck, tickling his skin until it’s collected by his collar and the claws in his shoulder dig just a bit deeper, prompting the ghost of a wince as he tries to stay impassive in front of this creature that was Not Quite Siegfried, but bore such likeliness to him, not in appearance but mannerisms, it clouds his judgement down to his trigger reactions.

It leans its head to the side, curtain of hair parting enough he can observe those shining, inhuman orange eyes fixed on him. His lips drip blood even while closed, a trail sliding down his neck instead of splattering onto the floor, staining his tan skin, torso bare and pockmarked by numerous scars and bruises already almost faded from the last time he was forcefully subdued just a few hours ago. He’d snapped the chains that tied him to the bed by sheer strength, the remnants still attached to manacles that hung heavy on his wrist.

Gran’s mask is up, covering his expression from the nose down as his lips twitch and open wider before closing. It removes his hand from the door, splinters following it as it opens his mouth just slightly and exposing the source of fresh blood on his lips, sharp teeth that don’t quite fit on a normal human mouth when closed.

That hand reaches up, fingers closing but for one long index that reaches up, sharp nail delicately hooking on the teal fabric and tugging it down, exposing Gran’s face fully to the feral creature that scrutinizes him. It bunches up on his chin and the captain tries to keep his breath level, expression unchanged as his free hand reaches into his pocket.

The moment his gloved fingers close around an object, it’s an obvious enough gesture Siegfried notices, eyes darting down and Gran makes his move, arm shooting out, shoulder twisting for him to elbow Siegfried in the face.

Something gives under his elbow with a loud crack and it makes him stagger enough Gran can follow up with a high kick, making the knight hit the frame of the bed he’d previously broken free from. Remnants of the chains used for his limbs still hang on the twisted header, tinkling loud enough to add to the sudden cacophony that is immediately overshadowed by a loud sound.

It’s not a roar, but close as Siegfried launches himself against the wall and Gran moves, discarding the potion cartridge of his weapon. His hand carefully holds onto the sedative as he takes a step ahead and headbutts the man, hard.

His head rings, vision blurry for a second but he has fought in worse conditions so it is muscle memory what allows him to exchange the cartridge on the weapon without looking at it, sedative loaded and ready to use. 

It’s enough for Siegfried to recover first, wide grip grabbing him by the front of his clothes, lifting him up, up, until his feet stop touching the floor and he kicks them in panic. He’s not choking him, but Gran scrabbles uselessly with his free hand, short nails doing nothing but carve light trails of red as they scratch and try to free himself.

Siegfried is smiling, and it is easily one of the more terrifying visions he’s witnessed in his life so far.

His nose is broken, crooked shape looking out of place but already the destroyed cartilage shifts underneath bloodstained skin. The miracle of dragon blood in action is enough to make him slightly nauseous, but the taller man seems to not even notice his face rearranging itself. 

His inhuman grin is wide enough Gran can see the gouges on his lips product of newly grown teeth before he averts his eyes somewhere else, darting across the room in a desperate bid to find something useful. Something to distract the creature that has him in its grip when he's tossed unceremoniously against the ruined bed. 

His head hits painfully against the metal, broken edge slicing an eyebrow before he can fully recover and stop the inertia from the crash. He glances down at his weapon, dismayed to find the tip of the syringe broken. It was designed in such a way to prevent the whole weapon rendered useless when used against too strong a hide or too many times, but replacing the needle was more time consuming than a cartridge. 

With Siegfried looming over him, it was an impossible task. 

His nose is healed now, crooked from not being set right and surrounded by fresh blood smeared on tan skin. His breathing is too loud as Siegfried advances leisurely towards him. The cut in his eyebrow stings and he’s forced to close his eye to prevent blood coming in.

There is only one thought ringing in his head, the same that has tormented Gran from the moment Siegfried ceased to respond to words but did not quite launch into destruction as back then.

What does he want?

It did not wish for rampage, or easily a dozen rooms would’ve been obliterated before they could get a handle on him. 

It wasn’t murder, or the claws that pull him up again from his clothes could easily puncture something vital in that moment, chains clinking all too loud in the tense moment. Siegfried could’ve easily killed him many times if he’d been serious while Gran had subdued him before and tried to now.

The man in question let out a strange sound. It wasn’t a growl, odd enough that the captain had no word for it. That loud breathing again, nostrils flared with each inhale as Siegfried presses his nose against the curve of Gran’s jaw-

He knows what it wants. 

The realization is enough to color his face red and a thrill to run down his spine. Now, in hindsight it is clear why he did not go on rampage but targeted Gran specifically, why he resisted being subdued by a large group of people, but did not, truly did not, harm Gran at all even when he’d broken his nose and retaliated on several ocassions alone with him.

The captain swallows, throat suddenly dry, palms sweating as Siegfried presses his nose against his neck and inhales. 

He was wrong. This was Siegfried, all of him, his basest desires exposed and offered for the taking. 

It would be a lie to say he hadn’t thought of this, in the darkest of nights and in plain daylight but hadn’t ever thought them to be-

Footsteps. Coming closer and hurried. Siegfried immediately changes his demeanor, snarl forming in his lips and Gran does not hesitate to grab him by his shoulder, pressing the older man against him. 

“Don’t come in! Everything is alright, but don’t come in!”

He hopes, he dearly hopes they listen to him. Siegfried struggles against his grip and he takes the chance to toss Siegfried on his back, digging his elbow on a bad bruise near his sternum and pressing his knee hard on his stomach.

It’s a cheap, dirty move but it is enough for him to take his weapon, jam the broken tip in between Siegfried’s angry show of teeth and pull the trigger, immediately making him choke with the sudden influx of liquid.

He coughs in an attempt to expel it, but Gran covers his mouth with a gloved hand, wincing at the claws shredding his coat and even creating some tears on the thick, monster proof scrubs he wore. But he doesn’t falter, not until he sees his throat move once, twice and the pain of the sharp nails on his back retreat.

_“Are you sure? Do you need backup?”_

“No! Whatever you do, don’t come in! I’ll come out when it’s safe!”

He yells in a hurry his answer, noticing how agitated Siegfried becomes when he hears the outsider. Instead he lowers his head, ready to test his theory and praying he does not get his face disfigured.

He bites Siegfried.

It’s not a savage bite by any stretch of reality, but enough to leave a red mark on the tender skin of his neck and a yelp in someone else. Here he gets instead that odd, unidentifiable sound again and a clawed hand on his hair, nail tips pressing against his scalp to shove him closer to Siegfried himself.

The captain eases his bite, soothing it with his tongue as he threads his other hand in those damp locks of hair and tugs harshly to expose his neck better. Siegfried smells of heat, sweat, musk. Of the bitter potion he forced him to drink, of fresh blood and adrenaline.

For someone who chases power in battle, it’s an intoxicating, shameful mixture to drown himself in. 

He wonders what does he smell of to Siegfried.

The grip in his scalp recedes slightly, signaling Gran that either the concoction or his actions are working. The potion will last even less than last time because it was drunk instead of injected, and he has no idea if Siegfried has developed some kind of tolerance to it but truthfully it’s the least of his worries when the struggle begins anew.

Gran is pulled away by the back of his tattered coat, almost falling on his back as Siegfried incorporates just slightly, wiping his mouth with the back of his hand and licking his lips.

At this point the white cloth is only hanging by his sleeves so he discards it along with his bag. The facemask also comes off, tossed aside to an unknown corner, only left with the still relatively intact scrubs underneath. 

There’s a large stretch of silence between them, both men gauging the other to know who will be the first one to break this impasse. 

In the end it’s Gran, bending his knee to take impulse and practically tackle the older man again, rolling against the hard wooden floor until finally he has Siegfried on his belly, the captain on top of him pulling on the chain fragments still attached to the manacles in his wrist.

Rather, Siegfried allowing him to do so. Even without this feral state, Siegfried would easily be able to throw him off in this position. But Siegfried doesn’t want to throw him off, even if it enjoys the struggle of it.

“If you wanted me to fuck you, you could’ve asked for it whenever you wanted you know?” He whispers against tense shoulder blades, tongue darting out and licking a stray drop of sweat that threatens to slide off and away. Siegfried jolts against him, something resembling a pleased hum resonating in his torso, stark and clear against Gran’s body,

Gloved fingers stray low, low enough to dip under the elastic of his pants, sliding them down, his bare bottom is exposed, then his full, strong thighs and leaves them hanging below his knees. The leather is warm but still cold against Siegfried’s skin, running feverish and high. Suddenly, he seizes up against Gran, nails scraping against wood and drawing splinters out. 

The captain has one finger inside his ass, aided by his heat to slide in effortlessly up to his second knuckle. Gran doesn't know if Siegfried likes the same as his but there is no time to second guess or to remember hidden fantasies to act out. No time for romanticism, no soft bed to cushion their lust, no warm lips to lose himself in and also track of time.

But there is the constant sound of approval coming from the man underneath as Gran works him open, holding the chain attached to one of his wrists, twisting his arm on his back to keep him in check.

Its an awkward position, but rewarding when those hips push against his fingers. The older man turns his head, face obscured by wild hair but for the bright, unnatural orange of those irises. 

Something akin to a moan echoes in the room when Gran adds a third finger, twisting them ceaselessly to hopefully distract him with enough pleasure to mount him without issues. 

He has no problem about getting hard enough to do so swiftly, not when his worry and fear have been lessened and overwhelmed by desire. Both to aid this man, and to relieve himself of the shameful excitement that plagued him from the first whiff of terror and closeness he exuded pressed against the door. 

Because he has thought about something like this, drowning in guilt and perversion in the darkest of nights. Siegfried without restrain and abandon, claiming him not with the tender touches he usually yearns for but barely any thought for him as he takes, takes and claims him as his. Until there is nothing in him that is not marked as the beast’s property.

The air is knocked out of him suddenly as Siegfried breaks his grip and reverses their position, hovering over him, wearing nothing but sweat and blood as he straddles Gran, the captain sitting and pressed against the wall.

Apparently he did not appreciate the lapse in thought of his partner. Selfishness, jealousy transparent in that displeased expression.

 _Look at me, only at me._

One wickedly sharp nail traces down his cheek, his chin. It leaves a thin, red trail as it scratches but not quite drawing blood yet. Down his neck, the hollow of his throat, the beginning of his sternum until it meets the tough fabric of his collar. It isn’t sliced effortlessly, drawing a frown on Siegfried’s face as he tries to cut the offending clothing away. 

Before the knight gets more impatient, Gran untucks his shirt from his pants, swiftly removing it and tossing it away. Siegfried wastes no time to lean down and gives him a matching bite on the juncture of his neck. There’s thoughtfulness, but his teeth are far too sharp to leave him unscatched as they cut through thin skin, blood running down in rivulets down bare skin.

Now it’s his turn to thread his fingers in Siegfried’s hair as Gran winces, involuntarily trying to shy away to no avail from the pain. 

And yet, underneath the current of pain, desire blooms in him, panting and groaning as his trousers are far too tight in this moment, the scent of his blood and Siegfried surrounding him until everything else is blotted out.

“Ah!” 

The teeth are drawn out, hot, wet tongue licking away at the wound to soothe it. It continues up the column of his neck, sending endless shivers from the wet warmth that gets closer to his ear, the gravelly sounds coming from his chest, the damp breath that heats his skin.

His gloved hands cup a handful of Siegfried’s ass, regretting for the briefest moment he did not remove them to feel taut skin against his bare palms, before withdrawing to fumble with his pants. He only gets as far enough to undo one button of his pants when Siegfried backs up slightly and finishes the job for him, popping them off by simply yanking them open.

“No, wait-“ He stops mid sentence, breath caught in his throat as those very dangerous hands free his erection from his underwear. 

The slight graze of those claws against the sensitive, red flesh of his hard dick is enough to make him dizzy and await with bated breath, both in anticipation and self preservation.

There’s no hesitation as Siegfried kicks away the remnants of his pants and lifts his hips, impaling himself in one swift motion. Those powerful thigh muscles swell with exertion as Gran strokes them up and down, feeling them work underneath his gloved fingers as breathy moans leave his mouth every time he exhales.

It’s just the beginning, but it’s already too much. He wants to lean forward and toss Siegfried on his back, fuck him with his legs over his shoulders, bending him in half and watch his dick bounce with each thrust against his toned stomach, smearing precum on tanned abdominals as the room fills with a litany of their sounds of pleasure.

It’s exactly what he does, chains tinkling and echoing slightly as they clash against themselves and the floor planks. Siegfried hits his head due to the quickness of the motion but it’s as if it didn’t happen. He’s not flexible enough for both legs over his shoulders, but one suffices only for Gran anyways, holding it in place and pushing down as he pistons in and back of his ass, panting and moaning mixing with those growls and the inhuman rumbling coming from him. 

His hair is lighter than the wood below, spread and taking on a slight orange tint that matches those feral eyes, slits trained on him. 

Siegfried tastes of bitterness, of blood.

Gran kisses him, those sharp teeth cutting into his lips as their tongues twist together, until he doesn’t know whose blood is he tasting, chanting his name as it’s the only thing left in his mind now. 

Nothing else matters in this moment but him.

“Siegfried...Siegfried!”

He isn’t going to last long, not with the pace his hips set as he craves more and more pleasure, not when the man feels so tight and slick around him, nothing his hand or fantasies could’ve ever given him in exchange for a fleeting scenario.

Siegfried is getting close too, those growls becoming heavy huffing as he wraps his hand around his dick. 

It’s thick and heavy, slick with precum already and he would give everything to have it inside his mouth at some point.

Instead Gran strokes it at an uneven rhythm, breaking off the kiss to pant in the curve of his neck as he’s reaching his limit. His hips stutter and his voice breaks in a short yell as he empties himself on the still wanting man, sharp nails digging in his back to bring him closer and desperate for release. 

A few more strokes and once Gran is lucid enough to breathe again, he bites Siegfried again in the tender skin of his neck. This time it’s hard enough for blood to bloom in his lips, and he comes with a keening sound. His back arches, pressing him closer to the captain as his legs shake, hands curling and digging in deeper his nails in tender skin but the younger man only winces and endures it.

It goes on for too many long seconds, until Siegfried relaxes entirely, as if the fight was completely drained out of him at all, panting loudly in exhaustion as sweat drips from his tired body and whining when Gran pulls out.

Semen drips from his used hole in such a tempting way, Gran feels a bit of drool threatening to escape his lips. 

His bag is within arms reach, and he swallows, aftertaste of sweat and blood fresh in his tongue when Siegfried rolls to his side and watches him, orange eyes still inhuman, but now with the trace of sentience in them.

What are you waiting for?, they seem to ask him. 

Gran reaches for his bag, slitted eyes observing as he withdraws vials from the bag and uncaps them. He drinks them all with only slight hesitation, grimacing at the bitter, acrid taste.

They were never meant to be ingested, only injected. Maddening Vitality would kick in shortly, and hopefully even with the reduced effects he’d be able to keep up with this feral man. 

Like a creature that exposes its belly to gain favor with its playmate and further amplified by the sedative, Siegfried stretches out fully, spreading his legs and exposing the length of his bruised neck to the captain.

_Come. Take me._

Gran obligues.

* * *

When he opens his eyes, there is darkness surrounding him. The stench of sweat, sex and blood hangs heavy in the air, making Siegfried scrunch his nose at the powerful assault.

And then he realizes, he’s in control again.

A warm body snores beside him and he doesn’t need light to know it’s the captain.

The destroyed bed was only large enough for one person, so Gran is sitting on the floor, head resting on the mattress, hand stretched until his fingertips graze Siegfried’s skin.

The knight incorporates slightly, noticing he’s covered pitifully by the tattered remnants of his coat, completely naked underneath. His eyes stray to the room, taking in the numerous marks of scuffles, clashes, parts where he’d gouged out chunks of wood with his nails while being fucked to oblivion.

Because he did remember everything. All of it, and he could not bring himself to regret any of it, not yet. 

A tentative smile forms in his face as he reaches out and holds the captain’s hand in his.

He doesn’t need to wonder if Gran does either. 


End file.
